Certain heat exchangers use a type of header made in two parts, known as a two-part header or a two-part header tank.
More specifically, this type of header comprises a lower first part or collector plate which comprises a bottom and longitudinal walls.
This type of header also comprises an upper part forming a cover, this upper part accepting flanges that form inlets and/or outlets for fluid passing through the exchanger and/or flanges that form fixing tabs to allow the exchanger to be fixed to a support.
A tube-type heat exchanger generally comprises one or two headers the lower part of which comprises parallel slots to accept the ends of the tubes through which the fluid passing through the exchanger flows, said fluid emerging via the end of said tubes into an interior volume of the header.
The various components of the exchanger are generally made of metal, notably of aluminum alloy, and are assembled by brazing. To ensure high quality brazing it is necessary for the components to be assembled with one another beforehand accurately.
Thus, the assembling of a heat exchanger involves numerous prior assembly steps. In the case of a two-part header an initial assembly between the lower and upper parts of the header, a second assembly between the inlet/outlet flanges and the upper part of the header and a third assembly between the upper part and the various fixing tabs are performed in addition to the assembling of the metal tubes.
These various assembly operations require two or three steps according to the modes of assembly known to those skilled in the art; the process of assembling the exchanger is therefore complicated especially since the assembly techniques use different technologies, notably crimping, clinching or even welding.
Thus there is a first known mode of assembly in which the cover is crimped by clips provided on the lower part, the inlet/outlet flange is for its part held in position by means of a flared joint with the cover and the tab is fixed by a clip of the tab passing through the wall of the cover.
Also known is a second mode of assembly in which the cover is also crimped to the lower part using clips arranged on the lower part, while the inlet/outlet flange is crimped using a clip arranged on the cover and the fixing tab is attached to the cover using TIG welding.
Also known is a third mode of assembly in which the cover is crimped into the lower part of the header while the inlet/outlet flange and the fixing tab are secured to the cover using clinching operations.